System For Syringe Engagement To An Injector

ABSTRACT

An injector system for injecting fluid includes a syringe and an injector. The syringe includes a body and a plunger movably disposed within the body. The plunger has at least one flexible leg extending toward the rearward end of the body. The injector has a housing with a front plate, a drive member at least partially disposed within the housing and operable to engage the plunger, and a syringe release assembly operable to release the syringe. The syringe assembly includes a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing and a plunger release tube surrounding at least a portion of the drive member. The plunger release tube has a first end rotationally engaged with the syringe release gear. Rotation of the syringe release assembly releases the at least one flexible leg from the drive member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. application Ser. No. 17/404,272, filed Aug. 17, 2021, which is a Continuation Application of U.S. application Ser. No. 17/073,574, filed Oct. 19, 2020, now U.S. Pat. No. 11,103,637, which is a Divisional Application of U.S. application Ser. No. 15/126,598, filed Sep. 16, 2016, now U.S. Pat. No. 10,806,852, which is a 371 Application of International Application No. PCT/US2015/21171, filed Mar. 18, 2015, which claims priority to U.S. Provisional Application No. 61/955,527, filed Mar. 19, 2014 and U.S. Provisional Application No. 61/970,018, filed on Mar. 25, 2014, the disclosures of which are incorporated herein by reference in their entirety.

BACKGROUND Field

This application relates to medical injectors and syringes, syringe interfaces, and syringe plungers for use therewith. More particularly, the present application relates to front-loading medical injectors and syringes, syringe interfaces, and syringe plungers for use with new or existing medical injectors such that the syringe is mountable upon and removable from the injectors by a syringe latch.

Description of Related Art

Medical injectors and syringes for injecting contrast media into a patient for imaging biological structures are known in the art. For example, with reference to FIG. 1, a conventional injector apparatus 10 for injecting a liquid contrast media into a vascular system of an animal is disclosed in U.S. Pat. No. 5,383,858, which is incorporated herein by reference. This injector apparatus 10 has a front-loading construction. The apparatus of FIG. 1 utilizes a syringe 12 capable of being front-loaded into a mounting assembly 14 associated with a front wall 16 of a housing 18 of an injector 20 by a first releasable mechanism 22. The syringe 12 is capable of functioning in an injection operation without the use of a pressure jacket (although the syringe may be used in an injector with a pressure jacket).

With continued reference to FIG. 1, the mounting assembly 14 is provided with an essentially cylindrical interface 26 for receiving a rearward end of the syringe 12. The interface 26 includes an annular surface 28, which may be cylindrical or conically tapered. The annular surface 28 includes a distal ledge, which is engaged by tabs 30 on the rearward end of the syringe 12. The syringe 12 is inserted into the cylindrical interface 26 until the tabs 30 engage the distal ledge to secure the syringe 12 to the injector 20.

The syringe 12 comprises an elongated main tubular body or barrel 32 and a coaxial discharge injection section 34, interconnected by an intermediate conical portion 36. A plunger 38 is slidably positioned within the tubular body 32 and is connectable to a second releasable mechanism 40 on a piston 42 in the injector housing 18. The second releasable mechanism 40 is formed in part by the plunger 38 and in part by the piston 42.

The piston 42 and plunger 38 cooperate to eject fluid contained within the syringe 12 in a desired quantity and at a desired rate. The second releasable mechanism 40 is designed to facilitate axial movement of the plunger 38 in either direction when actuated. The second releasable mechanism 40 is also designed to engage or disengage the plunger 38 from the piston 42 no matter where the plunger 38 sits in tubular body 32.

In operation, the syringe 12 is mounted by inserting the syringe 12 into the interface 26 in the mounting assembly 14. The tabs 30 initially move past the annular surface 28 where they engage the distal ledge to securely hold the syringe 12 to the mounting assembly 14. The mounting assembly 14 further includes a forwardly projecting annular ring or collar 44, which functions to assure perpendicular engagement between the plunger 38 and piston 42. As explained above, the forwardly projecting annular ring or collar 44 also functions as a seal between a resilient annular sealing flange 46 on the syringe 12 and the mounting assembly 14.

The resilient annular sealing flange 46 surrounds the tubular body 32 of the syringe 12 and is disposed forward of the tabs 30 a preselected distance essentially equal to a width of the annular surface 28. Thus, when the syringe 12 is inserted into the interface 26 in the mounting assembly 14 until the sealing flange 46 engages the annular ring 44, the annular ring 44 and flange 46 create a seal between the syringe 12 and the mounting assembly 14.

With further reference to FIG. 1, the apparatus also includes a system for transmitting syringe information from the syringe 12 to an injector controller 51. The syringe 12 is provided with an encoding device 48 forward of the tabs 30 but rearward of the flange 46. When attaching the syringe 12 to the mounting assembly 14, if the syringe 12 is rotated after the tabs 30 engage the distal ledge, a sensor 50 is provided in the annular surface 28 to read the encoding device 48. The sensor 50 then forwards the associated signals to the injector controller 51, which interprets the signals and modifies the function of the injector 20 accordingly. Examples of the information which could be encoded on the encoding device 48 include dimensions of the syringe 12, volume of the syringe 12, content of the syringe 12 (in the case of a pre-filled syringe), manufacturing information such as lot numbers, dates and tool cavity number, recommended contrast media flow rates and pressures, and loading/injection sequences.

As an alternative to the encoding device 48 being a bar code, the encoding device 48 also could include machine-readable raised or recessed surfaces. In addition, the tubular body 32 of the syringe 12 also may be provided with an indicating mechanism 52 for readily detecting the presence or absence of a liquid contrast media in the syringe 12. In this instance, the indicating mechanism 52 includes a plurality of integrally molded, textured dots on the syringe 12, which provide a visual indication of whether the syringe 12 contains liquid or air.

Accordingly, while the above injector and syringe apparatus have proven effective, the engagement reliability of the mounting assembly 14 discussed hereinabove was found to be insufficient. Accordingly, a need has arisen for a more reliable syringe/injector engagement interface.

SUMMARY

According to one aspect of the device of the present disclosure, provided is an injector system for injecting fluid that includes a syringe and an injector. The syringe includes: a body comprising a rearward end and a forward end; a plunger movably disposed within the body; at least one syringe drive paw positioned toward the rearward end of the body; and a syringe engagement flange positioned toward the rearward end of the body and extending around a circumference of the body. The injector includes: a housing having a front plate defining a syringe-receiving opening therein and a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe. The syringe latch has a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom. The syringe engagement flange pushes against the plurality of latch members of the syringe latch to open the syringe latch as axial rearward motion is applied to the syringe relative to the syringe latch and the plurality of latch members return to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing.

The injector may further include a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing. The syringe release gear may be mounted to a rear side of the front plate by at least one syringe release cam pin. The syringe release gear may also include an opening formed therein that is aligned with the syringe-receiving opening of the front plate. The opening in the syringe release gear may include a plurality of teeth formed around a circumference thereof. In addition, the syringe drive paw may be configured to engage the plurality of teeth of the opening of the syringe release gear.

The syringe may be disengaged from the injector after completion of an injection procedure by rotating the syringe. This causes rotation of the syringe release gear via the engagement between the syringe drive paw and the plurality of teeth of the syringe release gear. The plurality of latch members of the syringe latch are thereby forced into the open position which allows a user to remove the syringe from the housing of the injector. The syringe desirably includes two syringe drive paws that are positioned toward the rearward end of the body located 180° degrees apart.

The syringe latch may include two latch members, three latch members, or any other suitable number of latch members. Each of the plurality of latch members of the syringe latch may include a first portion and an arc-shaped second portion extending from the first portion. The arc-shaped second portion, when viewed in cross-section, may include a sloping face. The syringe latch may be manufactured from a polymeric material.

According to another aspect of the present disclosure, also provided is a method for engaging a syringe with an injector. The method includes: providing a syringe having a body with a rearward end and a forward end, a plunger movably disposed within the body, a syringe drive paw positioned toward the rearward end of the body, and a syringe engagement flange positioned toward the rearward end of the body and extending around a circumference of the body; providing an injector that includes a housing having a front plate defining a syringe-receiving opening therein, a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe; and a syringe latch mounted to a front side of the front plate and comprising a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom; applying axial rearward motion to the syringe relative to the syringe latch such that the syringe engagement flange pushes against the plurality of latch members of the syringe latch to open the syringe latch; and returning the plurality of latch members of the syringe latch to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing.

According to another aspect of the present disclosure, an injector system for injecting fluid may include a syringe having a body comprising a rearward end and a forward end, and a plunger movably disposed within the body, the plunger having at least one flexible leg extending toward the rearward end of the body. The injector system may further include an injector having

a housing having a front plate defining a syringe-receiving opening therein, a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe and releasably connect the at least one flexible leg to at least a portion of the drive member, a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing, the syringe release gear mounted to a rear side of the front plate, and a plunger release tube surrounding at least a portion of the drive member, the plunger release tube having a first end rotationally engaged with the syringe release gear. Rotation of the syringe release gear may rotate and axially move the plunger release tube relative to the drive member to engage the at least one flexible leg and release the at least one flexible leg from the drive member.

According to a further aspect of the present disclosure, the syringe release gear may be mounted to a rear side of the front plate by at least one syringe release cam pin. The syringe release cam pin may extend through the front plate. The syringe release gear may include an opening formed therein that is aligned with the syringe-receiving opening of the front plate. The opening in the syringe release gear may include a plurality of teeth formed around a circumference thereof. At least one syringe drive paw may be positioned toward the rearward end of the body and a syringe engagement flange may be positioned toward the rearward end of the body and extending around a circumference of the body. The injector may further include a syringe latch mounted to a front side of the front plate, the syringe latch comprising a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom, The syringe engagement flange may push against the plurality of latch members of the syringe latch to open the syringe latch as axial rearward motion is applied to the syringe relative to the syringe latch and the plurality of latch members return to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing. The syringe drive paw may be configured to engage a plurality of teeth formed on the syringe release gear. The syringe may be disengaged from the injector after completion of an injection procedure by rotating the syringe, which causes rotation of the syringe release gear via the engagement between the syringe drive paw and a plurality of teeth of the syringe release gear, thereby forcing the plurality of latch members into the open position and allowing a user to remove the syringe from the housing of the injector. Each of the plurality of latch members of the syringe latch may include a first portion and an arc-shaped second portion extending from first portion. The arc-shaped portion may include a slot formed therein. The syringe may include two syringe drive paws positioned toward the rearward end of the body and located 180° degrees apart.

According to another aspect of the present disclosure, a front-loading medical injector system may include a syringe having a body comprising a rearward end and a frontward end, and a plunger movably disposed within the body, the plunger having at least one flexible leg extending toward the rearward end of the body. The injector system may further include an injector having a housing having a front plate defining a syringe-receiving opening therein, a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe and releasably connect the at least one flexible leg to at least a portion of the drive member, and a syringe release assembly operable to release the syringe. Rotation of the syringe release assembly may release the at least one flexible leg from the drive member. The syringe release assembly may include a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing, the syringe release gear mounted to a rear side of the front plate, and a plunger release tube surrounding at least a portion of the drive member, the plunger release tube having a first end rotationally engaged with the syringe release gear. Rotation of the syringe release gear may rotate and axially move the plunger release tube relative to the drive member to engage the at least one flexible leg and release the at least one flexible leg from the drive member. The injector may further include a syringe latch mounted to a front side of the front plate for securing the syringe to the injector. The syringe latch may have a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom. At least one syringe drive paw may be positioned toward the rearward end of the body, and a syringe engagement flange may be positioned toward the rearward end of the body and extending around a circumference of the body. The syringe engagement flange may push against the plurality of latch members of the syringe latch to open the syringe latch as axial rearward motion is applied to the syringe relative to the syringe latch and the plurality of latch members return to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing. Each of the plurality of latch members of the syringe latch may include a first portion and an arc-shaped second portion extending from first portion.

These and other features and characteristics of the device of the present disclosure, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the device of the present disclosure. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a conventional injector system showing an injector housing and a syringe in a disassembled relationship;

FIG. 2 is a cross-sectional view of an injector system in accordance with an embodiment of the disclosure showing the syringe and the injector housing in a partially disassembled relationship;

FIG. 3 is a top plan view of the syringe latch in accordance with an embodiment of the disclosure for connecting the syringe to the injector housing;

FIGS. 4A-4E are cross-sectional views of a portion of the injector system of FIG. 2 illustrating the steps required for loading a syringe into the injector housing;

FIG. 5 is a cross-sectional view of the injector system of FIG. 2 showing the syringe and the injector housing in the assembled state;

FIG. 6 is a cross-sectional view of the injector system of FIG. 2 taken along line B-B;

FIG. 7 is a cross-sectional view of the injector system of FIG. 2 taken along line A-A;

FIGS. 8A-8D are cross-sectional views of a portion of the injector system of FIG. 5 illustrating the steps required for unloading a syringe from the injector housing;

FIG. 9 is a perspective view of an injector in accordance with an alternative embodiment of the disclosure;

FIG. 10 is a perspective view of the injector of FIG. 9 having the faceplate removed such that an alternative embodiment of the syringe latch is visible;

FIG. 11 is a perspective view of the injector of FIG. 10 with syringes attached thereto;

FIG. 12 is a perspective view of the injector of FIG. 9 with syringes attached thereto;

FIG. 13 is a side view of a syringe configured to be used with the injector of FIG. 9; and

FIG. 14 are front views of the syringe latch of the injector of FIG. 9.

DETAILED DESCRIPTION

For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and derivatives thereof, shall relate to the device of the present disclosure as it is oriented in the drawing figures. However, it is to be understood that the device of the present disclosure may assume various alternative variations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the device of the present disclosure. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

With reference to FIG. 2, an injector system 100 for injecting a liquid contrast media into a vascular system of an animal is provided. The injector system 100 has a front-loading construction. The system of FIG. 2 utilizes a syringe 102 capable of being front-loaded into a mounting assembly 104 associated with a front plate 106 of a housing (not shown) of an injector 108 by a first releasable mechanism 22. The syringe 102 is capable of functioning in an injection operation without the use of a pressure jacket (although the syringe may be used in an injector with a pressure jacket).

The syringe 102 includes an elongated main tubular body or barrel 110 and a coaxial discharge injection section 112 interconnected by an intermediate conical portion 114. A plunger 116 is slidably positioned within the tubular body 110 and includes at least one plunger connect flex leg 118 that is connectable to a piston/plunger interface 120 on a piston 122 of the injector 108. The plunger 116 also includes a plunger sense interrupter 123 extending from a central portion thereof in the direction of the at least one flex leg 118. The plunger sense interrupter 123 is configured to interrupt a light path produced by an IR transmitter 140 and IR receiver 142 through a fiber optic cable 144 extending along the length of the piston 122, thereby providing a signal to an injector controller (not shown) that the syringe 102 is fully seated within the injector 108. An alternative embodiment of the plunger sense interrupter 123 determines the presence/absence of the syringe 102 without the use of a fiber optic cable.

The syringe 102 further includes a syringe engagement flange 124 positioned toward the rearward end of the body 110 and extending around a circumference of the body 110. When viewed in cross-section, the syringe engagement flange 124 includes a sloping section 126, a shoulder section 128 extending from the sloping section 126 that is essentially perpendicular to an exterior surface of the body 110 of the syringe 102, and an engagement section 130 extending from the shoulder section 128. The engagement section 130 is configured to engage a plurality of teeth 132 of an opening 134 of a syringe release gear 136 of the injector 108 as discussed in greater detail hereinafter in relation to FIG. 6.

Since the syringe 102 is being used in this embodiment without a pressure jacket, for strength and visibility of the contents of the syringe 102, the syringe 102 may be formed of a clear PET polyester material. In the alternative, the wall of the syringe 102 may be formed of polypropylene reinforced by providing a series of annular ribs on the tubular body 110 of the syringe 102 in a longitudinally spaced relationship. In addition, the syringe 102 desirably includes an encoding device for providing information regarding the syringe 102 to the injector 108 an indicating mechanism for readily detecting the presence or absence of a liquid contrast media in the syringe 102 similar to the encoding device and indicating mechanism of syringe 12 discussed hereinabove.

With continued reference to FIG. 1, the injector includes a housing (not shown) having the front plate 106 defining a syringe-receiving opening 138 therein. The piston 122 is positioned within the housing and is configured to extending into and out of the syringe-receiving opening 138 under the power of a drive mechanism 146. The piston 122 includes the piston/plunger interface 120 at an end thereof that is operable to interact with the at least one flex leg 118 of the plunger 116 to engage the plunger 116 disposed within the syringe 102.

With reference to FIG. 3 and with continuing reference to FIG. 2, the injector 108 also includes a syringe latch 148 mounted to a front side of the front plate 106 by any suitable fastening device 150 for maintaining the syringe in the seated position within the injector 108. The syringe latch 148 comprises a substantially oval shaped body member 152 and a plurality of latch members 154 extending toward a center C of the body member 152. In the embodiment of the syringe latch 148 illustrated in FIG. 3, two latch members 154 are included. The syringe latch 148 is desirably manufactured from a resilient, polymeric material such that the latch members 154 are configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom.

Each of the plurality of latch members 154 of the syringe latch 148 includes a first portion 156 extending from the body member 152 and an arc-shaped second portion 158 extending from the first portion 156 and configured to engage the syringe engagement flange 124 of the syringe 102. The arc-shaped second portion 158, when viewed in cross-section, may include a sloping face 160 (see FIGS. 4A-4E) that engages with the sloping section 126 of the syringe engagement flange 124 to force the syringe latch 148 into the open position.

With continued reference to FIG. 2, the injector 108 also includes the syringe release gear 136 that forms an enclosure 162 for receiving the syringe 102 when the syringe 102 is fully seated within the injector housing. The syringe release gear 136 is mounted to a rear side of the front plate 106 by at least one syringe release cam pin 164. The syringe release cam pin 164 is configured to be connected to the syringe release gear 136 and extend through the front plate 106 of the injector 108 into a slot 166 in the arc-shaped second portion 158 of the latch members 154 of the syringe latch 148.

With reference to FIG. 7 and with continued reference to FIG. 2, the piston 122 is surrounded by a plunger release tube 168. The plunger release tube 168 has a first end that is rotationally engaged with the syringe release gear 136 such that rotation of the syringe release gear 136 causes rotation of the plunger release tube 168.

The process for engaging a syringe 102 with the injector 108 to form an injector system 100 is illustrated in FIGS. 4A-4E. This process allows for syringe engagement with an injector 108 that provides a syringe engagement adapted to releasably engage the syringe 102 with the injector 108 regardless of the rotational orientation of the syringe 102 with respect to the injector 108. The syringe engagement uses the flex legs 118 attached to the back side of the plunger 116 of the syringe 102 and a corresponding feature on the piston 122 of an injector 108 that provides axial engagement that does not require any specific rotational orientation of the syringe 102 to releasably engage with the injector 108. Additionally, a feature (i.e., the syringe engagement flange 124) is provided on the outside surface of the rear portion of the tubular body 110 to transfer rotational movement of the syringe into a release mechanism (i.e., the syringe release gear 136) implemented in the injector 108 releasing both the syringe 102 and the plunger 116 regardless of the axial position of the engaged syringe plunger 116.

The first step in the process for engaging the syringe 102 with the injector 108 is shown in FIG. 4A in which the syringe 102 is positioned axially with the syringe-receiving opening 134 of the front plate 106 of the injector 108 and is moved axially along the piston 122 into the enclosure 162 formed by the syringe release gear 136 in the direction of arrow A₁. With reference to FIG. 4B, as the syringe 102 is inserted, the sloping section 126 of the syringe engagement flange 124 engages the sloping face 160 of the arc-shaped second section 158 of the latch members 154 of the syringe latch 148 and pushes the syringe latch 148. In addition, with reference to FIGS. 4C and 4D, as the syringe 102 is inserted, the sloped surface of the piston/plunger interface 120 flexes the at least one flex leg 118 of the plunger 116 open. With reference to FIG. 4E, continual movement of the syringe 102 in the direction of arrow A₁ causes the syringe 102 to be fully seated within the enclosure 162 formed by the syringe release gear 136. When the body of the syringe 102 is fully seated within the enclosure 162 formed by the syringe release gear 136, the following items occur: first, the engagement section 130 of the syringe engagement flange 124 engages the teeth 132 of the syringe release gear 136. In addition, the syringe engagement flange 124 moves beyond the arc-shaped second portion 158 of the latch members 154 of the syringe latch 148, thereby closing the syringe latch 148 to retain the syringe 102. Desirably, when the syringe latch 148 returns to the closed position, it provides an audible “click” to indicate to the operator that the syringe 102 has been installed on the injector 108. Furthermore, the flex legs 118 on the plunger 116 flex closed engaging the piston/plunger interface 120. Finally, the plunger sense interrupter 123 of the plunger 116 interrupts the light path produced by an IR transmitter 140 and IR receiver 142 through a fiber optic cable 144 extending along the length of the piston 122, thereby providing a signal to an injector controller (not shown) that the syringe 102 is fully seated within the injector 108.

Removal of the syringe 102 from the injector 108 upon the completion of an injection procedure requires that the syringe 102 be rotated, as described below. This operation is illustrated in and described by reference to FIGS. 8A-8D.

With reference to FIG. 8A and FIG. 8B, the rotation of the syringe 102 causes rotation of the syringe release gear 136 via the engagement between the engagement section 130 of the syringe engagement flange 124 and the plurality of teeth 132 of the syringe release gear 136 as shown in FIG. 6. This rotation, in turn, causes rotation of the syringe release cam pins 164 along the slots 166 provided in the latch members 154 of the syringe latch 148 as shown in FIG. 8C. The latch members 154 of the syringe latch 148 are thereby forced into the open position.

As also shown in FIG. 8C, the rotation of the syringe release gear 136 also rotates the plunger release tube 168 about the piston 122 since the plunger release tube 168 is coupled to the syringe release gear 136 as described hereinabove. The rotation of the plunger release tube 168 about the piston 122 causes a cam action at a release cam surface 170 (see FIGS. 1 and 5) causing an axial extension of the plunger release tube 168 towards the syringe-receiving opening 134 of the front plate 106. The axial extension of the plunger release tube 168 forces the at least one flex leg 118 of the plunger 116 to flex open to release the piston/plunger interface 122.

At this point, a user can remove the syringe 102 from the housing of the injector 108. Once the syringe 102 is removed, the syringe release gear 136 returns to original position allowing the syringe latch 148 to return to the closed position and the plunger release tube 168 to drop down as shown in FIG. 8D.

While the syringe latch 148 discussed hereinabove includes two latch members, this is not to be construed as limiting the disclosure as any suitable number of latch members may be utilized. For instance, with reference to FIGS. 9-14, the injector may be embodied as a dual syringe injector system 200 that includes a pair of syringes 202 a, 202 b and an injector 204. As shown in FIGS. 10 and 11, the injector 204 utilizes a syringe latch 206 a, 206 b for each of the syringes 202 a, 202 b that includes three latch members 208 for engaging the syringe 202 a, 202 b within the injector 204. In addition, rather than having the latch members 208 connected to a body member as with the syringe latch 148 discussed hereinabove, each of the latch members 208 is independent and utilizes a spring return 210 (see FIG. 14).

More specifically, with reference to FIGS. 13 and 14, a syringe 202 a, 202 b for use with injector 204 includes a body 212 comprising a rearward end 214 and a forward end 216; a plunger (not shown) movably disposed within the body 212; and at least one syringe drive paw 218 positioned toward the rearward end 214 of the body 212. Desirably, the syringe 202 a, 202 b includes a pair of syringe drive paws 218 at the rearward end 214 of the body 212 located 180° apart. The syringe 202 a, 202 b also includes a syringe engagement flange 220 positioned toward the rearward end 214 of the body 212 and extending around a circumference of the body 212.

The injector 204 includes a pair of syringe latches 206 a, 206 b mounted to a front side of the front plate thereof. Each of the syringe latches 206 a, 206 b comprises a plurality of latch members 208 extending toward a center of the syringe-receiving opening 222 and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom. The syringe engagement flange 220 pushes against the plurality of latch members 208 of the syringe latch 206 a, 206 b to open the syringe latch 206 a, 206 b as axial rearward motion is applied to the syringe 202 a, 202 b relative to the syringe latch 206 a, 206 b and the plurality of latch members 208 return to the closed position to retain the syringe 202 a, 202 b within the opening 222 of the injector 204 when the syringe 202 a, 202 b is fully seated within the injector 204.

The syringe 202 a, 202 b may be disengaged from the injector 204 after completion of an injection procedure by rotating the syringe 202 a, 202 b. This causes rotation of a syringe release gear 224 via the engagement between the syringe drive paws 218 and a plurality of teeth of the syringe release gear 224. The rotation of the syringe release gear 224 activates the spring returns 210, which force the latch members 208 of the syringe latch 206 a, 206 b into the open position, thereby allowing a user to remove the syringe 202 a, 202 b from the injector 204.

While specific embodiments of the device of the present disclosure have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the device of the present disclosure which is to be given the full breadth of the claims appended and any and all equivalents thereof. 

We claim:
 1. An injector system for injecting fluid, comprising: a syringe, comprising: a body comprising a rearward end and a forward end; a plunger movably disposed within the body; at least one syringe drive paw positioned toward the rearward end of the body; and a syringe engagement flange positioned toward the rearward end of the body and extending around a circumference of the body; and an injector, comprising: a housing having a front plate defining a syringe-receiving opening therein and a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe; and a syringe latch comprising a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom, wherein the syringe engagement flange pushes against the plurality of latch members of the syringe latch to open the syringe latch as axial rearward motion is applied to the syringe relative to the syringe latch and the plurality of latch members return to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing.
 2. The injector system of claim 1, wherein the syringe latch comprises a substantially oval-shaped body member and the plurality of latch members extend toward a center of the body member.
 3. The injector system of claim 1, wherein each of the plurality of latch members of the syringe latch comprise a first portion and an arc-shaped second portion extending from the first portion.
 4. The injector system of claim 3, wherein the arc-shaped second portion, when viewed in cross-section, comprises a sloping face.
 5. The injector system of claim 4, wherein the sloping face of the arc-shaped second portion engages with the syringe engagement flange to force the syringe latch into the open position.
 6. The injector system of claim 1, wherein the syringe latch is manufactured from a polymeric material.
 7. The injector system of claim 1, wherein the syringe latch comprises three latch members.
 8. The injector system of claim 7, wherein the three latch members are evenly spaced around the center of the syringe-receiving opening.
 9. The injector system of claim 1, wherein the injector further comprises a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing.
 10. The injector system of claim 9, wherein the syringe release gear comprises an opening formed therein that is aligned with the syringe-receiving opening of the front plate.
 11. The injector system of claim 10, wherein the opening in the syringe release gear comprises a plurality of teeth formed around a circumference thereof and the at least one syringe drive paw is configured to engage the plurality of teeth of the opening of the syringe release gear.
 12. The injector system of claim 11, wherein the syringe is disengaged from the injector after completion of an injection procedure by rotating the syringe, thereby causing rotation of the syringe release gear via the engagement between the at least one syringe drive paw and the plurality of teeth of the syringe release gear such that the plurality of latch members of the syringe latch are forced into the open position which allows a user to remove the syringe from the housing of the injector.
 13. An injector system for injecting a fluid, comprising: a syringe, comprising: an elongated tubular body comprising a rearward end and a forward end; a plunger movably disposed within the tubular body, the plunger having at least one flexible leg extending toward the rearward end of the tubular body; a syringe engagement flange positioned toward the rearward end of the tubular body and extending around a circumference of the tubular body, the syringe engagement flange comprising: a sloping section; and an engagement section adjoined with the sloping section; a fluid injector, comprising: a housing having a front plate defining a syringe-receiving opening therein and a drive member at least partially disposed within the housing and operable to engage the plunger disposed within the syringe; and a syringe latch comprising a plurality of latch members extending toward a center of the syringe-receiving opening and configured to move from a closed position to an open position when a force is applied thereto and from the open position to the closed position when the force is removed therefrom, wherein the sloping section of the syringe engagement flange pushes against the plurality of latch members of the syringe latch to open the syringe latch as axial rearward motion is applied to the syringe relative to the syringe latch and the plurality of latch members return to the closed position to retain the syringe within the opening of the housing when the syringe is fully seated within the housing.
 14. The injector system of claim 13, wherein the syringe latch comprises a substantially oval-shaped body member and the plurality of latch members extend toward a center of the body member.
 15. The injector system of claim 13, wherein each of the plurality of latch members of the syringe latch comprise a first portion and an arc-shaped second portion extending from the first portion.
 16. The injector system of claim 15, wherein the arc-shaped second portion, when viewed in cross-section, comprises a sloping face.
 17. The injector system of claim 16, wherein the sloping face of the arc-shaped second portion engages with the sloping section of the syringe engagement flange to force the syringe latch into the open position.
 18. The injector system of claim 13, wherein the syringe latch comprises three latch members.
 19. The injector system of claim 18, wherein the three latch members are evenly spaced around the center of the syringe-receiving opening.
 20. The injector system of claim 13, wherein the injector further comprises a syringe release gear that forms an enclosure for receiving the syringe when the syringe is fully seated within the housing.
 21. The injector system of claim 20, wherein the syringe release gear comprises an opening formed therein that is aligned with the syringe-receiving opening of the front plate.
 22. The injector system of claim 21, wherein the opening in the syringe release gear comprises a plurality of teeth formed around a circumference thereof and the engagement section of the syringe engagement flange is configured to engage the plurality of teeth of the opening of the syringe release gear.
 23. The injector system of claim 22, wherein the syringe is disengaged from the injector after completion of an injection procedure by rotating the syringe, thereby causing rotation of the syringe release gear via the engagement between the engagement section and the plurality of teeth of the syringe release gear such that the plurality of latch members of the syringe latch are forced into the open position which allows a user to remove the syringe from the housing of the injector. 